A source tells Star magazine Britney Spears’ pending nuptials to Kevin Federline are going to be so secretive, codes will be used to prevent location info from getting into the wrong hands. “Britney and Kevin are going to incredible lengths to keep the ceremony a secret,” the insider said. “Intended guests were called by a wedding planner, who didn’t give her name. She asked for the guests’ addresses and told them that they would be mailed an invitation in mid-September. She also asked each invited guest his or her mother’s maiden name and assigned each person a secret code number. On the eve of the wedding, each guest will get a phone call and they’ll be asked their mothers’ maiden name and secret code. If they answer correctly, they’ll be directed to a secret location – a parking lot – where they can leave their cars. Security guards will check their details again, and only then will they be bussed to the wedding.” The wedding is rumored to be happening between now and late October.